This invention relates to a compressor or vacuum pump comprising: a casing having a cooling gas inlet and a cooling gas outlet for allowing a cooling gas to flow therethrough; a fan mounted at the cooling gas inlet, comprising a fan housing and configured to blow said cooling gas into said casing; a compression or vacuum chamber comprising a first housing, a process gas inlet and a process gas outlet for allowing a process gas to flow therethrough and at least one rotating element; a driving module comprising a second housing and at least one bearing for supporting said at least one rotating element; a silencer comprising a cover and configured to attenuate noise generated by the compressor or vacuum pump.
Maintaining the temperature of different components of a compressor or vacuum pump under control is a challenge the designers are faced with.
While some of the existing designs are extracting the air from inside the casing of a compressor or vacuum pump and blowing said air into the surrounding environment, other designs use the convection capabilities of different cover materials used to manufacture the components.
An example can be found in US 2009/0 194 177 A1, in the name of Hitachi Koki Co., disclosing a layout for an air compressor using two fans for creating two flows of air and cooling different zones of the compressor unit.
Because the design uses two fans, the casing is provided with three different areas for allowing air to enter within the casing and three other areas for allowing air to flow out of said casing and into the outside environment.
By providing three inlets and three outlets the manufacturing of the casing also gets more complicated, since additional cuts and finishing steps will have to be performed. In some cases such inlets and outlets generate weak structural points for the casing. Because of this, additional reinforcements need to be added, fact that increases the manufacturing time and implicitly the manufacturing costs.
Another drawback of such a design is the complexity of layout, since each of the two fans will have to be connected to a driving unit.
Another example can be found in U.S. Pat. No. 4,283,167 A, in the name of Varian Associates, disclosing a vacuum pump comprising a fan taking air from the outside environment and directing it towards the pump casing. The casing further comprises vertically and horizontally extending fins along its surface, for cooling purposes.
Tests have shown that, during the functioning of a vacuum pump, different temperature areas are being formed between its components, and adjacent positioned components will influence each other's temperature. One of the drawbacks of the above identified vacuum pump is the fact that such areas are not determined or treated differently in terms of cooling. Because of this the cooling process becomes not efficient.
Furthermore, because of the influence of different adjacent positioned components, materials with a high thermal resistance need to be chosen for elements that would not necessarily require it, which increases the manufacturing costs of the unit. On the other hand, if such materials would not be used, the high temperatures involved in the vacuum process would wear them prematurely.
Taking the above mentioned drawbacks into account, it is an object of the present invention to provide a compressor or vacuum pump that would efficiently maintain a desired temperature of its components.
In is another object of the present invention to provide a compressor or vacuum pump with a smaller footprint than the existing units and with a simpler layout.
Further, the present invention aims to increase the lifetime of the components used, and also to reduce the risk of different adjacent components to influence each other's temperature.
Another object of the present invention is to provide an easy to assemble and disassemble compressor or vacuum pump. Because of this, the manufacturing and the maintenance time can be reduced.